Many of the protesters were from Cambodia, where Prime Minister Hun Sen has dominated politics for 30 years.

As U.S. President Barack Obama greeted leaders of the 10 members of the Association of Southeast Asian Nations at the Sunnylands estate in Rancho Mirage, California Monday, protesters outside said they want human rights at the top of the agenda.

Obama told the leaders gathered for the two-day summit on trade and security issues that his administration has rebalanced its foreign policy toward Asia and the Pacific. “This has included engagement with Southeast Asia and ASEAN, which is central to the region’s peace and prosperity,” the president said, “and to our shared goal of building a regional order where all nations play by the same rules.”

Among the hundreds of protesters outside, many were from Cambodia, where Prime Minister Hun Sen has dominated politics for 30 years. “We are here today to send a clear message to Hun Sen that we don't support communists, we don't support a dictator, we don't support a tyrant,” said Bona Chhith of the Cambodian American Alliance. “Hun Sen must go,” he said.

A police officer looks on as protesters line one side of a roadway leading to Sunnylands where U.S. President Obama prepares to host leaders from Southeast Asia at the ASEAN Summit in Rancho Mirage, California, Feb. 15, 2016.

Others criticized the government of Laos, and Vietnam's dominance over Laos and its others neighbors. “Vietnam, go home,” said one protester. “Laos belongs to Laos.”

The 2014 coup in Thailand drew protests over the inclusion in the meeting of the Thai prime minister, Prayut Chan-o-cha. Thai-American Chao Suethae said of the country's leader, a former general, “He shouldn't come to [such a] free land as the United States. The dictator should not stay in this free country.”

An American who served in the US Army during the Vietnam War, Ruben Treviso of the American GI Forum, worried that the sacrifice of fallen soldiers would be in vain if these trade talks are not tied “to human rights.”

Protesters line one side of a roadway leading to Sunnylands where U.S. President Obama prepares to host leaders from Southeast Asia at the ASEAN Summit in Rancho Mirage, California, Feb. 15, 2016.

Inside the meeting, President Obama said they are. Four ASEAN members have joined the US-led Trans-Pacific Partnership, and Mr. Obama said that “in joining the TPP, Singapore, Vietnam, Malaysia and Brunei have committed to high labor and environmental standards.”

The standards, the protesters say, are not high enough. “TPP allows for corporations to offshore jobs to countries with the weakest environmental protections where it's easiest to exploit workers and create a downward momentum in wages here in the United States,” said Lua Masumi of the Citizens Trade Campaign, a coalition of labor and rights groups.

Obama said the talks will create opportunities for workers in the United States and Southeast Asia. The demonstrators say they're not convinced.

Protesters line one side of a roadway leading to Sunnylands where U.S. President Barack Obama prepares to host leaders from Southeast Asia at the ASEAN Summit in Rancho Mirage, California, Feb. 15, 2016.